Pb with function taxo2phylog (package ade4)

Hello

 I'm using the package ade4 to obtain classification from a .txt file. I 
use the following commands:
cronquist <- read.table("cronquist.txt", h = T, row.names = 8)
cronquist <- as.taxo(cronquist[7:1])
cro.phy <- taxo2phylog(cronquist)

in which cronquist.txt is a file with a classification of 218 genus of tree 
species from french Guiana.
We I try to use the function taxo2phylog, I obtain the following error 
message (in French) :
Erreur dans newick2phylog.addtools(res) : la longueur de 'dimnames' [2] 
n'est pas ??gale ?? l'??tendue du tableau
Error in newick2phylog.addtools(res) : length of dimnames[2] is not equal to 
length of frame

newick2phylog.addtools is a function that is called when taxo2phylog is 
called

when I want to know what is in dimnames[2] I obtain the names of my columns 
: none is missing.

I don't understand what's happening because I've already been using this 
function with other files and I  had no problem
Can someone help me?

Thanks

Christophe Girod